The present invention is directed to methods and devices for metering flowable material. As used herein, flowable material includes fluids (i.e., liquids and gasses), particularly liquids, semi-liquids, and mixtures of liquids and solids; and other material capable of flowing including particulate, granular, and powdered material.
Flow control devices generally known to the art are exemplified by U.S. Pat. Nos. 998,543; 1,287,756; 1,594,021; 2,177,265; 3,605,794; 4,338,961; 4,711,376; and 5,337,775. The needle valve type devices disclosed in the art do not provide accurate control of fluids flowing at a continuous, but relatively low, flow rate. Moreover, precise adjustments to vary the flow of materials of differing viscosities is difficult.
Typical devices for holding containers and discharging the contents thereof are exemplified by the following patents: U.S. Pat. Nos. 173,203; 482,574; 533,687; 547,466; 692,434; 711,705; 1,595,329; 3,814,293; and 5,285,989.
It is the primary object of the present invention to provide improved methods and apparatus for controlling and adjusting the rate at which flowable materials supplied to a metering device are discharged from the device in a predetermined, continuous metered flow. It is a further object of the present invention to provide improved means for controlling the flow rate of material through a metering device and for compensating for variations in viscosity of different materials flowing through the device. It is another object of the invention to provide a portable flow control device requiring only a relatively low energy input for operation, and which is disposable after one use.
Other objects, features and advantages of the device in accordance with the present invention will become apparent from the following discussion.